September 24, 2007
Clear Skies
Clear skies prevailed during today's observations. A rising boundary layer can be observed, reaching up to 2 km at 19:00 UTC. A residual layer of aerosols is observed, mixing with today's boundary layer, around 2 km from 14:00-19:00 UTC. Dark red counts, after 19:00 UTC, at 3.5 km are due to clouds that advected over ELF. Hourly PM 2.5 concentrations in the range of 23 to 36.4 ug/m3 [AQI Levels: 66-92 (Moderate)] were recorded at Maryland's Department of the Enviroment Oldtown site in Baltimore during ELF's operation.